LED Drivers for LCD Backlights
Backlight LED Driver
for Small LCD Panels (Charge Pump Type)
No.11040EBT22
BD1601MUV
●Description
The multi-level brightness control white LED driver not only ensures efficient boost by automatically changing the boost rate
but also works as a constant current driver in 64 steps, so that the driving current can be adjusted finely. This IC is best
suited to turn on white LEDs that require high-accuracy LED brightness control.
●Features
1) Built-in parallel LED driver for 4 to 6 lamps.
2) 64-step LED current adjust function.
3) Inter-LED relative current accuracy: 3% or less
4) Lighting/dimming control via a single-line digital control interface.
5) Automatic transition charge pump type DC/DC converter (×1,×1.5 and ×2).
6) High efficiency achieved (90% or more at maximum).
7) Various protection functions such as output voltage protection, over current limiter and thermal shutdown circuit are mounted.
8) Small QFN package.
●Applications
This driver is applicable for various fields such as mobile phones, portable game machines and white goods.
●Absolute Maximum Ratings
(Ta=25℃)
Parameter
Symbol
Ratings
Unit
VMAX
7
V
Operating temperature range
Topr
-30 ~ +85
℃
Storage temperature range
Tstg
-55 ~ +150
℃
Pd
700 (*1)
mW
Power supply voltage
Power dissipation
(*1) When a glass epoxy substrate (70mm × 70mm × 1.6mm) has been mounted,
this loss will decrease 5.6mW/℃ if Ta is higher than or equal to 25℃.
●Operating Conditions
(Ta = -30 ~ 85℃)
Parameter
Operating power supply voltage
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Symbol
Ratings
Unit
VCC
2.7~5.5
V
1/12
2011.06 - Rev.B
Technical Note
BD1601MUV
●Electrical Characteristics
Unless otherwise noted, Ta = +25℃, VBAT=3.6V
Parameter
Symbol
Limits
Min.
Typ.
Max.
Units
Condition
Overall
Input voltage range
Vin
2.7
3.6
5.5
V
VBAT terminal
Quiescent Current
Iq
-
0.1
1
μA
EN=0V
Current Consumption1
Idd1
-
1.0
2.4
mA
x1.0 Mode, Except LED current
Current Consumption2
Idd2
-
2.5
3.5
mA
x2.0 Mode, Except LED current
fOSC
0.8
1.0
1.2
MHz
LED maximum current
ILED-max
28.5
30
31.5
mA
LED current accuracy
ILED-diff
-
-
5.0
%
ILED-match
-
0.5
3.0
%
VLED
-
0.2
0.25
V
Low threshold voltage
VIL
-
-
0.4
V
High threshold voltage
VIH
1.4
-
-
V
High level Input current
IIH
-
0.1
2
μA
EN=Vin
Low level Input current
IIL
-2
-0.1
-
μA
EN=0V
Minimum EN High time
THI
50
-
-
nsec
Minimum EN Low time
TLO
0.05
-
100
μsec
EN Off Timeout
TOFF
-
512
640
μsec
Charge Pump
Oscillator frequency
Current Source
LED current matching (*1)
LED control voltage
When LED current 15.5mA setting
and LED terminal voltage 1.0V
When LED current 15.5mA setting
and LED terminal voltage 1.0V
minimum voltage
at LED1~LED4 pins
Logic control terminal
(*1) The following expression is used for calculation:
ILED-match={(Imax-Imin)/(Imax+Imin)} × 100
Imax= Current value in a channel with the maximum current value among all channels
Imin=Current value in a channel with the minimum current value among all channels
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2/12
2011.06 - Rev.B
Technical Note
BD1601MUV
●Block Diagram
C1N
C1P
C2N
C2P
×1, ×1.5, ×2
Charge pump
VBAT
VOUT
Over Voltage
Protect
Charge Pump
Mode Control
OSC
EN
Enable/
Vout Control
Brightness
Control
LED1
TSD
LED2
LED3
6
LED4
Current
DAC
GND
Fig.1 Block Diagram
9 C1N
10 C2N
11 C2P
12 GND
●Pin Configuration
LED3 15
6 VOUT
LED4 16
5 NC
GND 4
7 VBAT
EN 3
LED2 14
NC 2
8 C1P
NC 1
LED1 13
Fig. 2 Pin Configuration
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3/12
2011.06 - Rev.B
Technical Note
BD1601MUV
●Pin Descriptions
Pin No.
Pin name
In/Out
Type
1
NC
-
-
No connect
2
NC
-
-
No connect
3
EN
In
C
ON/OFF and dimming control
4
GND
-
D
GND
Function
5
NC
-
-
No connect
6
VOUT
Out
A
Charge pump output
7
VBAT
-
A
Power supply
8
C1P
In/Out
A
Flying capacitor pin positive (+) side
9
C1N
In/Out
B
Flying capacitor pin negative (-) side
10
C2N
In/Out
B
Flying capacitor pin negative (-) side
11
C2P
In/Out
A
Flying capacitor pin positive (+) side
12
GND
-
D
GND
13
LED1
Out
-
LED current driver output 1
14
LED2
Out
B
LED current driver output 2
15
LED3
Out
B
LED current driver output 3
16
LED4
Out
B
LED current driver output 4
Type-A
Type-B
PAD
PAD
GND
VBAT
Type-C
VBAT
PAD
GND
GND
Type-D
VBAT
PAD
Fig.3 Equivalent circuit diagram for ESD
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4/12
2011.06 - Rev.B
Technical Note
BD1601MUV
●Typical Application Circuit
White LED Application(Recommended)
C2
C2P
C1P
C2N
C1N
C1
Battery
×1, ×1.5, ×2
Charge pump
VBAT
Cin
=1μF
VOUT
Cout
=1μF
Over Voltage
Protect
Charge Pump
Mode Control
EN
Pulse
Generator
OSC
Enable/
Brightness
Control
Vout Control
LED1
TSD
LED2
LED3
6
LED4
Current
DAC
Vf
GND
Fig. 4 Block Diagram and Recommended Circuit Example.
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5/12
2011.06 - Rev.B
Technical Note
BD1601MUV
●Reference Data
3.0
1.2
Ta=85 oC
0.8
o
Ta=-30 oC
Ta=25 C
0.4
100
2.5
90
Ta=85 oC
2.0
1.5
1.0
Ta=25 C
0.5
3
3.5
4
4.5
5
2.5
5.5
3
3.5
Fig.5 Circuit Current
(Standby)
80
70
70
EFFICIENCY [%]
4.5
5
5.5
40
2.5
60
Ta=25 oC
30
100
Ta=-30 oC
Ta=25 oC
50
Ta=85 oC
40
30
50
30
10
Fig.10 Efficiency
(30mA × 4Lights
2.0
1.5
15.0
1.5
Ta=-30 oC
Ta=25 oC
Ta=85 oC
1.0
DNL [LSB]
12.5
Ta=25 oC
10.0
0
2.5 3.0 3.5 4.0 4.5 5.0 5.5 6.0 6.5 7.0
Input voltage: Vin[V]
5.5
2.0
Ta=-30 oC
17.5
3.5
4.0
4.5
5.0
Input voltage: Vin[V]
Fig.9 Efficiency
(15mA × 4 Lights)
Fig.8 Efficiency
(5mA × 4Lights)
20.0
3.0
Ta=85 oC
7.5
0.5
0.0
0.5
0.0
-0.5
5.0
-1.0
-1.0
2.5
-1.5
-1.5
0.0
-2.0
0.4
0.8
1.2
1.6
LED voltage: VLED [V]
2.0
-2.0
0
Fig.11 LED Current Characteristics
(LED current 15.5mA)
10
20
30
40
50
STATE[DEC]
60
0
Fig.12 LED Current Characteristics
(Differential Linearity error)
5.0
20.0
4.5
Ta=-30 oC
Ta=25 oC
Ta=85 oC
1.0
-0.5
0.0
Ta=85 oC
40
20
5.5
5.5
60
10
3.5
4.0
4.5
5.0
Input voltage: Vin[V]
5
70
10
0
2.5
4.5
Ta=-30 oC
80
60
4
Ta=25 oC
90
20
3.0
3.5
Fig.7 Efficiency
(20mA × 4Lights)
20
0
2.5
3
Input voltage: Vin[V]
INL [LSB]
EFFICIENCY [%]
4
90
80
Ta=85 oC
Up
50
100
Ta=-30 oC
40
60
Fig.6 Circuit Current
(operation in × 1.0Mode)
100
50
70
Input voltge: Vin[V]
Input voltage: Vin[V]
90
80
EFFICIENCY [%]
2.5
LED current [mA]
Ta=-30 oC
o
0.0
0.0
10
20
30
40
50
STATE[DEC]
60
Fig.13 LED Current Characteristics
(Integral Linearity Error)
Ta=-30 oC
17.5
4.0
15.0
3.5
3.0
Ta=-30 oC
2.5
o
Ta=25 C
2.0
1.5
1.0
LED current [mA]
LED current matching [%]
Down
EFFICIENCY [%]
1.6
Current Consumption: Idd1[mA]
Quiescent current: Iq[μA]
2.0
12.5
Ta=25 oC
10.0
o
Ta=85 C
7.5
5.0
2.5
0.5
Ta=85 oC
0.0
0
10
20
30
40
50
STATE[DEC]
0.0
60
Fig.14 LED current matching
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2.5
3
3.5
4
4.5
5
Input voltage: Vin[V]
5.5
Fig.15 LED Current – Input voltage
(LED current 15.5mA)
6/12
2011.06 - Rev.B
Technical Note
BD1601MUV
●Function Description
(1) LED driver
▪ UPIC interface
BD1601MUV is a single line digital interface control (Uni-port Interface Control=UPIC) that can control the power
ON/OFF and LED current value through the EN pin only. The LED current increments by about 0.5mA depending on the
number of leading edges. When the number of leading edge is added at the maximum output current of 30mA (64
leading edges), the current is almost equal to 0.5mA at startup time. To maintain any output current, the EN pin must be
kept at “H” level. To power off, the EN pin must be kept at “L” level for more than 640µsec.
THI
TLO
TOFF
EN
(Internal)
C1
State
C2
C3
C3
C4
C5
C63
C64
C1
C2
29.5mA 30mA
ILED
Soft Start
2.3mA
1.4mA 1.9mA
1.4mA
OFF
0.5mA 0.9mA
OFF
Fig.16 Brightness Control Method
THI
TLO
TOFF
EN
Fig.17 UPIC Interface
▪ LED current level
The LED current state can be changed by the EN control signal. When the current level is Cn, the basic LED current
(ILED) can be obtained from the following expression (where, n indicates a state number).
ILED = 30 / 64 ×n [mA]
State
Output current
State
Output current
State
Output current
State
Output current
[mA]]
[mA]
[mA]
[mA]
C1
0.5
C14
8.0
C33
15.5
C49
23.0
C2
0.9
C18
8.4
C34
15.9
C50
23.4
C3
1.4
C19
8.9
C35
16.4
C51
23.9
C4
1.9
C20
9.4
C36
16.9
C52
24.4
C5
2.3
C21
9.8
C37
17.3
C53
24.8
C6
2.8
C22
10.3
C38
17.8
C54
25.3
C7
3.3
C23
10.8
C39
18.3
C55
25.8
C8
3.8
C24
11.3
C40
18.8
C56
26.3
C9
4.2
C25
11.7
C41
19.2
C57
26.7
C10
4.7
C26
12.2
C42
19.7
C58
27.2
C11
5.2
C27
12.7
C43
20.2
C59
27.7
C12
5.6
C28
13.1
C44
20.6
C60
28.1
C13
6.1
C29
13.6
C45
21.1
C61
28.6
C14
6.6
C30
14.1
C46
21.6
C62
29.1
C15
7.0
C31
14.5
C47
22.0
C63
29.5
C16
7.5
C32
15.0
C48
22.5
C64
30.0
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7/12
2011.06 - Rev.B
Technical Note
BD1601MUV
(2) Charge pump
a) Description of operations
Pin voltage comparison takes place at Vout control section, and then Vout generaton takes place so that the LED
cathode voltage with the highest Vf is set to 0.2V. A boost rate is changed automatically to a proper one at the Charge
Pump Mode Control section so that operation can take place at possible low boost rate. When the current taken from
VBAT exceeds 600mA, the overcurrent limiter is activated and this IC is reset. In addition, if the output voltage falls
below 1.5V, this IC is reset for short-circuit at output.
b) Soft start function
BD1601MUV have a soft start function that prevents the rush current.
TOFF
EN/LED*
VOUT
ILED
Soft Start
Ordinal mode
Fig.18 Soft Start
c) Automatic boost rate change
The boost rate automatically switches to the best mode.
* (×1 mode -> ×1.5 mode) or (×1.5 mode -> ×2 mode)
If a battery voltage drop occursBD1601MUV cannot maintain the LED constant current, and then mode transition begins.
* (×1.5 mode -> ×1 mode) or (×2 mode -> ×1.5 mode)
If a battery voltage rise occurs, VOUT and VBAT detection are activated, and then mode transition begins.
(3) UVLO (Ultra low Voltage Lock Out)
If the input voltage falls below 2.2V, BD1601MUV is shut down to prevent malfunction due to ultra-low voltage.
(4) OVP (Over Voltage Protection)
This circuit protects this IC against damage when the C/P output voltage (VOUT) rises extremely for some external factors.
(5) Thermal shutdown (TSD)
To protect this IC against thermal damage or heat-driven uncontrolled operations, this circuit turns off the output if the chip
temperature rises over 175℃. In addition, it turns on the output if the temperature returns to the normal temperature.
Because the built-in thermal protection circuit is intended to protect the IC itself, the thermal shutdown detection
temperature must be set to below 175℃ in thermal design.
(6) Power sequence
VBAT
EN
Fig.19 Power sequence
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8/12
2011.06 - Rev.B
Technical Note
BD1601MUV
●Application Circuit Example
White LED Application(VOUT not used)
C2P
C2N
C1P
C1N
Battery
×1, ×1.5, ×2
Charge pump
VBAT
Cin
=1μF
VOUT
Cout
=1μF
Over Voltage
Protect
Charge Pump
Mode Control
EN
Pulse
Generator
OSC
Enable/
Brightness
Control
VDD
Vout Control
LED1
TSD
LED2
LED3
6
LED4
Current
DAC
Vf
GND
Fig. 20 Block Diagram and Circuit Example
●Application Parts Selection Method
Capacitor (Use a ceramics capacitor with good frequency and temperature characteristics.)
Symbol
Recommended value
Recommended parts
Type
Cout,Cin,C1,C2
1μF
GRM188B11A105KA61B(MURATA)
Ceramics capacitor
Connect an input bypass capacitor Cin between VBAT and GND pin and an output capacitor Cout between VOUT and GND
pin in proximity. Place both C1P-C1N and C2P-C2N capacitors in proximity to the chip. Furthermore, select a ceramics
capacitor with a sufficient rating for voltage to be applied.
When the parts not listed above are used, the equivalent parts must be used.
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9/12
2011.06 - Rev.B
Technical Note
BD1601MUV
●Recommended PCB Layout
In PCB design, wire the power supply line in a way that the PCB impedance goes low and provide a bypass capacitor if needed.
To substrate
GND
GND
Cout
GND
C2
C2
GND
VBAT
VOUT
EN
C1
Cin
CIN
C1
Cout
To substrate
VCC
VOUT
Fig.21 Application Layout Image (Top View)
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VBAT
Fig.22 BD1601MUV Front (Top View)
10/12
2011.06 - Rev.B
Technical Note
BD1601MUV
●Notes for use
(1) Absolute Maximum Ratings
An excess in the absolute maximum ratings, such as supply voltage, temperature range of operating conditions, etc., can
break down devices, thus making impossible to identify breaking mode such as a short circuit or an open circuit. If any
special mode exceeding the absolute maximum ratings is assumed, consideration should be given to take physical safety
measures including the use of fuses, etc.
(2) Operating conditions
These conditions represent a range within which characteristics can be provided approximately as expected. The
electrical characteristics are guaranteed under the conditions of each parameter.
(3) Reverse connection of power supply connector
The reverse connection of power supply connector can break down ICs. Take protective measures against the breakdown due
to the reverse connection, such as mounting an external diode between the power supply and the IC’s power supply terminal.
(4) Power supply line
Design PCB pattern to provide low impedance for the wiring between the power supply and the GND lines. Furthermore,
for all power supply terminals to ICs, mount a capacitor between the power supply and the GND terminal. At the same
time, in order to use an electrolytic capacitor, thoroughly check to be sure the characteristics of the capacitor to be used
present no problem including the occurrence of capacity dropout at a low temperature, thus determining the constant.
(5) GND voltage
Make setting of the potential of the GND terminal so that it will be maintained at the minimum in any operating state.
Furthermore, check to be sure no terminals are at a potential lower than the GND voltage including an actual electric transient.
(6)Short circuit between terminals and erroneous mounting
In order to mount ICs on a set PCB, pay thorough attention to the direction and offset of the ICs. Erroneous mounting can
break down the ICs. Furthermore, if a short circuit occurs due to foreign matters entering between terminals or between
the terminal and the power supply or the GND terminal, the ICs can break down.
(7) Operation in strong electromagnetic field
Be noted that using ICs in the strong electromagnetic field can malfunction them.
(8) Inspection with set PCB
On the inspection with the set PCB, if a capacitor is connected to a low-impedance IC terminal, the IC can suffer stress.
Therefore, be sure to discharge from the set PCB by each process. Furthermore, in order to mount or dismount the set
PCB to/from the jig for the inspection process, be sure to turn OFF the power supply and then mount the set PCB to the
jig. After the completion of the inspection, be sure to turn OFF the power supply and then dismount it from the jig. In
addition, for protection against static electricity, establish a ground for the assembly process and pay thorough attention
to the transportation and the storage of the set PCB.
(9) Input terminals
In terms of the construction of IC, parasitic elements are inevitably formed in relation to potential. The operation of the
parasitic element can cause interference with circuit operation, thus resulting in a malfunction and then breakdown of the
input terminal. Therefore, pay thorough attention not to handle the input terminals, such as to apply to the input terminals
a voltage lower than the GND respectively, so that any parasitic element will operate. Furthermore, do not apply a voltage
to the input terminals when no power supply voltage is applied to the IC. In addition, even if the power supply voltage is
applied, apply to the input terminals a voltage lower than the power supply voltage or within the guaranteed value of
electrical characteristics.
(10) Ground wiring pattern
If small-signal GND and large-current GND are provided, It will be recommended to separate the large-current GND
pattern from the small-signal GND pattern and establish a single ground at the reference point of the set PCB so that
resistance to the wiring pattern and voltage fluctuations due to a large current will cause no fluctuations in voltages of the
small-signal GND. Pay attention not to cause fluctuations in the GND wiring pattern of external parts as well.
(11) External capacitor
In order to use a ceramic capacitor as the external capacitor, determine the constant with consideration given to a
degradation in the nominal capacitance due to DC bias and changes in the capacitance due to temperature, etc.
(12) Thermal shutdown circuit (TSD)
When junction temperatures become 175℃ (typ) or higher, the thermal shutdown circuit operates and turns a switch OFF.
The thermal shutdown circuit, which is aimed at isolating the LSI from thermal runaway as much as possible, is not aimed
at the protection or guarantee of the LSI. Therefore, do not continuously use the LSI with this circuit operating or use the
LSI assuming its operation.
(13) Thermal design
Perform thermal design in which there are adequate margins by taking into account the permissible dissipation (Pd) in
actual states of use.
(14) Coil selection
To reduce the loss, select a coil with a small wound resistor for DC/DC converter output.
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11/12
2011.06 - Rev.B
Technical Note
BD1601MUV
●Ordering part number
B
D
1
Part No.
6
0
1
M
Part No.
U
V
-
Package
MUV: VQFN016V3030
E
2
Packaging and forming specification
E2: Embossed tape and reel
VQFN016V3030
<Tape and Reel information>
3.0±0.1
3.0±0.1
0.5
5
13
8
12
The direction is the 1pin of product is at the upper left when you hold
( reel on the left hand and you pull out the tape on the right hand
)
4
16
0.75
E2
9
1.4±0.1
0.4±0.1
1
3000pcs
(0.22)
1.4±0.1
+0.03
0.02 −0.02
1.0MAX
S
C0.2
Embossed carrier tape
Quantity
Direction
of feed
1PIN MARK
0.08 S
Tape
+0.05
0.25 −0.04
1pin
(Unit : mm)
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Reel
12/12
Direction of feed
∗ Order quantity needs to be multiple of the minimum quantity.
2011.06 - Rev.B
Notice
Notes
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consent of ROHM Co.,Ltd.
The content specified herein is subject to change for improvement without notice.
The content specified herein is for the purpose of introducing ROHM's products (hereinafter
"Products"). If you wish to use any such Product, please be sure to refer to the specifications,
which can be obtained from ROHM upon request.
Examples of application circuits, circuit constants and any other information contained herein
illustrate the standard usage and operations of the Products. The peripheral conditions must
be taken into account when designing circuits for mass production.
Great care was taken in ensuring the accuracy of the information specified in this document.
However, should you incur any damage arising from any inaccuracy or misprint of such
information, ROHM shall bear no responsibility for such damage.
The technical information specified herein is intended only to show the typical functions of and
examples of application circuits for the Products. ROHM does not grant you, explicitly or
implicitly, any license to use or exercise intellectual property or other rights held by ROHM and
other parties. ROHM shall bear no responsibility whatsoever for any dispute arising from the
use of such technical information.
The Products specified in this document are intended to be used with general-use electronic
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